An internal combustion engine often includes a turbocharger that is driven by exhaust. Japanese Laid-Open Patent Publication No. 2008-267257 describes a turbine housing that is a part of such a turbocharger. An outer shell covers the outer surface of the turbine housing, and engine coolant is supplied to the clearance between the outer surface of the housing and the outer shell. The clearance functions as a medium passage, which is supplied with coolant that cools the turbine housing through heat exchange.